To remove the fuel tank from early model Fleetwood, Deville, Eldorado, and Seville vehicles, start by disconnecting the negative battery cable and relieving the fuel system pressure, followed by draining the fuel tank. Remove the fuel filler door assembly and disconnect the screw retaining the filler pipe-to-body bracket, then raise the vehicle and support it with jackstands. Detach the tank level sender lead connector and support the tank with a transmission jack or equivalent before removing the two tank retaining straps. Lower the tank enough to disconnect the ground lead and fuel hoses from the pump assembly, then carefully remove the tank to ensure all connections and hoses are disconnected. For installation, use a new fuel pump O-ring gasket to install the pump/sender assembly into the tank, ensuring the strainer does not block the float arm's full travel. Place the tank on the jack, position the sound insulators, and raise the tank to attach the electrical and hose connectors. Raise the tank to the proper position and loosely install the retaining straps, tightening them to 26 ft. lbs. (35 Nm) once the tank is correctly positioned. Connect the grounding strap and negative battery cable, then turn the ignition key to the ON position with the engine OFF to check for fuel leaks at the tank. For later models, disconnect the negative battery cable and relieve the fuel system pressure before raising the vehicle and supporting it with jackstands. Drain the fuel tank and detach the fuel feed and return quick-connect fittings by twisting the connections to loosen dirt, blowing out any debris if compressed air is available, and squeezing the plastic tabs to pull the connections apart. Detach the fuel sender electrical connector, then, with assistance, support the tank and remove the fuel tank strap retaining nuts and bolts, placing the tank in a suitable work area. For installation, position and support the tank with assistance, install the fuel tank straps and retaining nuts and bolts, tightening them to 26 ft. lbs. (34 Nm). Install the vapor pipe, attach the fuel sender electrical connector, and reconnect the fuel feed and return quick-connect fittings, applying a few drops of clean engine oil to the male connector pipe ends to ensure proper reconnection and prevent leaks. Push the connectors together until the retaining tabs snap into place, then pull on both ends of each connection to ensure they are secure. Lower the vehicle, turn the ignition switch to the ON position for 2 seconds, then to OFF for 5 seconds, and again turn to ON to check for leaks.
Posted by GMPartsGiant Specialist 
